Submarine oil well production apparatus

ABSTRACT

The present invention relates to a submergible apparatus for producing an oil or gas well beneath the surface of a body of water which comprises an oil and gas separator having a pair of elongated horizontal ballast tanks attached thereto and means for selectively filling the ballast tanks with water or air. A pair of movable buoyancy vessels are attached to the separator and means for selectively moving the buoyancy vessels to alternate positions with respect to the separator are provided so that the apparatus has maximum stability while being towed on the surface of the body of water or submerged therein. A closed instrument capsule is removably attached to the separator which includes a liquid level controller for maintaining the liquid level within the separator at a desired level and means are provided for adjusting the liquid level controller from the outside of the instrument capsule.

United States Patent McMinn et al.

SUBMARINE 01L WELL PRODUCTION APPARATUS [75] lnventors: Robert E.McMlnn; Paul M.

Tournoux, both of Oklahoma City, Okla; Donald S. Mflnes, Chessington,England [73] Assignee: Black, Sivnlls & Bryson, Inc.,

Oklahoma City, Okla.

[22] Filed: Apr. 5, 1972 211 Appl. No.: 241,143

[52] US. Cl 55/164, 166/5 [51] Int. Cl. B0111 19/00 [58] Field of Search55/36, 45, 160, 164,

[56] Reierences Cited UNITED STATES PATENTS 2,767,802 10/1956 Orrell55/174 X Primary Examiner-Samih N. Zaharna Assistant Examiner-Richard W.Burks Attorney-Jerry .l. Dunlap, Cv Clark Dougherty et all [57] STRALTThe present invention relates to a submergible apparatus for producingan oil or gas well beneath the surface of a body of water whichcomprises an oil and gas separator having a pair of elongated horizontalballast tanks attached thereto and means for selectively filling theballast tanks with water or air. A pair of movable buoyancy vessels areattached to the separator and means for selectively moving the buoyancyvessels to alternate positions with respect to the separator areprovided so that the apparatus has maximum stability while being towedon the surface of the body of water or submerged therein. A closedinstrument capsule is removably attached to the separator which includesa liquid level controller for maintaining the liquid level within theseparator at a desired level and means are provided for adjusting theliquid level controller from the outside of the instrument capsule.

Patented Aug. 28, 1973 3,754,380

5 Sheets-Sheet l q. in F El /A k I'll Patented Aug. 28, 1973 5Sheets-Sheet 2 Patented Aug. 28, 1973 5 Sheets-Sheet 5 WJ H W SUBMARINEOIL WELL PRODUCTION APPARATUS BACKGROUND OF THE INVENTION 1. Field ofthe Invention The present invention relates generally to a submergibleoil well production apparatus, and more particularly, but not by way oflimitation, to a submergible oil and gas separator apparatus forproducing a well beneath the surface of a body of water. I

2. Description of the Prior Art The production of offshore oil and gaswells presents severe economic problems in that elaborate offshoreplatforms are generally required. Such platforms are used to supportseparation, dehydration, storage and other equipment required forproducing the wells and are very costly to manufacture, install andmaintain.

It has been proposed to utilize underwater production equipment locatedat each individual offshore well to reduce the number of offshoreplatforms required. For example, the installation of an underwater oiland gas separator at each offshore well head location would bring abouta substantial reduction in platform space required. However, theinstallation and successful operation of such submergible separatorapparatus presents severe technical problems, e.g., the apparatus mustbe capable of being towed on the surface of the water to a desiredlocation and then submerged and installed on the sea bed or ocean floor.Further, once submerged and placed on the bottom, the apparatus must becapable of stabilizing itself during operation and it must be capable ofresurfacing for service or change to a new well location. In addition,the apparatus must be capable of prolonged operation without the needfor outside power, and major control functions must be adjustable fromoutside the apparatus during the operation.

By the present invention a submergible oil well production apparatus isprovided having the above mentioned capabilities.

SUMMARY OF THE INVENTION The present invention relates to a submergibleapparatus for producing a well beneath the surface of a body of waterwhich comprises an oil and gas separator having a well stream inlet, gasoutlet, oil outlet and a liquid level controller connection disposedtherein. A pair of elongated horizontal ballast tanks are attached tothe separator and means are provided for selectively filling the tankswith water or air thereby providing ballast or buoyancy to theapparatus. A pair of movable buoyancy vessels are attached to oppositesides of the separator and positioned so that the center of buoyancy ofthe apparatus is above the center of gravity thereof. Means forselectively moving the buoyancy vessels to alternate positions areprovided attached to the buoyancy vessels so that the distance betweenthe centers of buoyancy and gravity of the apparatus may be changed toprovide maximum stability to the apparatus while being towed on thesurface of the body of water or submerged therein. A removableinstrument capsule is attached to the separator, the capsule including aliquid level controller connection and oil inlet and outlet connections.Liquid level control means are disposed within the instrument capsulefor generating a control signal proportional to the variance between theactual liquid level within the separator and the desired liquid level,the liquid level control means being connected to the liquid levelcontroller connection of the capsule. A conduit is provided removablyconnecting the liquid level controller connections of the separator andthe instrument capsule, and a conduit is removably connected between theoil outlet of the separator and the oil inlet of the instrument capsule.Valve means responsive to the control signal generated by the liquidlevel control means are provided for controlling the flow rate of oilremoved from the separator and the liquid level maintained therein, thevalve means being disposed within the instrument capsule and connectedbetween the oil inlet and outlet connections thereof. Means foradjusting the liquid level control means with respect to the desiredliquid level to be maintained in the separator from outside theinstrument capsule are provided attached to the instrument capsule.

It is, therefore, a general object of the present invention to provide asubmarine oil well production apparatus.

A further object of the present invention is the provision of asubmergible apparatus for producing an oil well beneath the surface of abody of water which may be towed on the surface to the well location andthen submerged without requiring the utilization of a barge mountedcrane or other ancillary equipment.

Yet a further object of the present invention is the provision of asubmergible oil and gas separator which may be installed and operated onthe sea bed or ocean floor and then economically recovered for serviceor relocation.

Another object of the present invention is the provision of an oil andgas separator apparatus which may be towed on the surface of a body ofwater, submerged therein and operated on the bottom with maximumstability.

Still another object of the present invention is the provision of asubmarine oil and gas separator apparatus which may be operated on thesea bed or ocean floor for long periods of time without the need foroutside power and wherein the major control functions of the separatormay be adjusted from outside the apparatus by divers during theoperation thereof.

Other and further objects, features and advantages of the presentinvention will be readily apparent to those skilled in the art from thefollowing description of preferred embodiments when taken in conjunctionwith the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of theapparatus of the present invention,

FIG. 2 is a top plan view of the apparatus of FIG. 1,

FIG. 3 is a side elevational view of the apparatus of FIG, ll,

FIG. 4 is an elevational view of one end of the apparatus of FIG. 3,

FIG. is an elevational view of the other end of the apparatus of FIG. H,

FIG. 6 is a diagrammatic view illustrating the flow of the variousstreams through the separator and instrument capsule of the apparatus ofFIG. 1 and the operation of the instruments within the instrumentcapsule,

FIG. 7 is a diagrammatic view of the hydraulic control system of thepresent invention for selectively moving the buoyancy vessels of theapparatus of FIG. I, and

FIG. 8 is a diagrammatic view of the ballast control system of thepresent invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to the drawingsand particularly to FIGS. 1 through 5, the submergible oil wellproduction apparatus of the present invention is illustrated andgenerally designated by the numeral 10. The apparatus 10 basicallycomprises a horizontal oil and gas separator 12 having a forward end 14and a rearward end 16. A pair of elongated ballast tanks 18 and 211 areprovided positioned parallel to each other and parallel to the axis ofthe separator 12. The ballast tank 18 is connected to the separator 12by a plurality of support members 22, and the ballast tank 20 isconnected to the separator 12 by a plurality of support members 24. Ascan be best seen in FIGS. 4 and S, the ballast tanks 18 1 and 20 arepositioned in a horizontal plane a distance below the separator 12 and aplurality of horizontal support members 26 are connected between thetanks 18 and 20.

A pair of movable buoyancy vessels 28 and 30 are attached to theseparator 12 by supporting arm assemblies 32 and 34 respectively. Asbest shown in FIGS. 2 and 3, the supporting arm assembly 32 is comprisedof a central arm 36 rigidly connected at one end 38 thereof to thebuoyancy vessel 28 and hinged at the other end 40 thereof to theseparator 12 for movement in a plane perpendicular to the axis of theseparator 12. A hydraulic jack assembly 42 for moving the arm 36 andbuoyancy vessel 28 is pivotally attached to the central portion of thearm 36 and to the ballast tank 18. A

pair of outer arms 44 and 46 are provided on either side of the centralarm 36. The outer arms 44 and 46 are rigidly attached to the buoyancyvessel 28 and hinged to the separator 12. A plurality of cross members48 are provided connected between the central arm 36 and outer arms 44and 46 to provide overall strength to the arm assembly 32.

The supporting arm assembly 34 is identical to the assembly 32 andincludes a central arm 50 rigidly attached to the buoyancy vessel 30 atone end and hinged to the separator 12 at the other end. A hydraulicjack assembly 52 is provided attached to the central portion of the arm50 and to the ballast tank 24, and a pair of outer arms 54 and 56 areprovided attached to the buoyancy vessel 30 and hinged to the separator12. Cross members 58 connect the central and outer support arms 50, 54and 56 together to provide strength to the assembly 34.

As shown in FIGS. 1, 2, 4 and 5, a pair of tie bars 60 are removablyconnected to each of the buoyancy vessels 28 and 30 and to the ballasttanks 18 and 20 respectively. As will be described further hereinbelow,the tie bars 60 retain the buoyancy vessels 28 and 30 in the properposition for towing the apparatus 10 on the surface of a body of water.

The separator 12 includes an access passage or manway 62 positioned onthe top thereof and a pair of hydraulic oil surge tanks 64 and 66, theoperation of which will be described below, are mounted on top of theseparator 12 at the rearward end 16 thereof. The separator 12 includes adrain connection 68 and a well stream inlet connection 70 positionednear the end 16 thereof. A gas outlet connection 72, an oil outletconnection 74 and a pair of liquid level controller connections 76 areprovided in the separator 12 at the forward end 14 thereof.

An instrument capsule 80 containing the various instruments required forcontrolling the operation of the separator 12 is removably attached tothe support member 26 in front of the end 14 of the separator 12. Theinstrument capsule 80 includes a pair of liquid level controllerconnections 82, a gas inlet connection 84, an oil inlet connection 86, agas outlet connection 87, an oil outlet connection 88, a well streaminlet connection and a well stream outlet connection 92. In addition, aplurality of observation ports 94 are disposed in the sides of theinstrument capsule 80 and three horizontal bars 96 are provided forhandling the capsule during installation and removal thereof.

As can be best seen in FIGS. 2 through 5, the well stream inletconnection 90 of the instrument capsule 80 is connected to a conduit 98by means of a conventional connector 100 and a shutoff valve 102 isprovided in the conduit 98. In operation of the apparatus 10, theconduit 98 is connected to the manifold of a well to be produced. Thewell stream outlet connection 92 of the capsule 80 is connected to aconduit 104 by means of a connector 106 and the conduit 104 is connectedto the well stream inlet connection 70 of the separator 12. A mainshutoff valve 112 and a bleed valve are disposed in the conduit 104. Aconduit 114 is provided connected to the conduits 98 and 104 between theshutofi' valves 102 and 112 so that the safety shutdown valve 168 may bebypassed. A bypass valve 116 is disposed in the conduit 114.

Oil separated within the separator 12 is removed therefrom by way of theoil outlet connection 74 thereof and a conduit 118 is connected to theoil inlet connection 86 of the instrument capsule 80 by way of aconnector 126. A shutoff valve 120 and a bleed valve 124 are disposed inthe conduit 1 18. The oil outlet connection 88 of the instrument capsule80 is connected to a conduit 128 by means of a connector 130 and ashutoff valve 129 is disposed in the conduit 128.

Gas separated within the separator 12 is removed therefrom by way of thegas outlet connection 72 thereof and a conduit 132 which is connected tothe gas inlet connection 84 of the instrumentcapsule 80 by a connector140. A shutoff valve 134 and a bleed valve 138 are disposed in theconduit 132. A conduit 142 is connected to the gas outlet connection 87of the instrument capsule 80 by a connector 144 and a shutoff valve 143is disposed in the conduit 142.

A pair of conduits 146 connect the liquid level controller connections76 of the separator 12 to the liquid level controller connections 82 ofthe instrument capsule 80 by way of a pair of connectors 154. Theconduits 146 each have a shutoff valve 148 and a bleed valve 152disposed therein.

A portion of the space between the ballast tanks 18 and 20 and thesupport members 26 positioned therebetween is enclosed to form a centralfloat (FIG. 2), and as best shown in FIGS. 3 and 5, a regulator float162 is attached to the central float at a position below the separator12. The ballast tanks 18 and 20, the central float 160 and the regulatorfloat 162 are connected to a ballast control system containing a varietyof conduits and valves which is used for selectively filling ordischarging the ballast tanks and floats with water ballast. Thisballast control system is primarily contained within the central float160 between the ballast tanks 18 and 20, and therefore, is not shown inFIGS. 1 through 5. However, it will be understood that a ballast controlmanifold is provided positioned on the apparatus in an easily accessiblelocation. The ballast control system is schematically shown in FIG. 8and will be described in detail hereinbelow.

A hydraulic control system for selectively moving the buoyancy vessels28 and 30 is connected to the hydraulic fluid accumulator tanks 64 and66 and the hydraulic jacks 42 and 52. This hydraulic control system isnot shown in FIGS. 1 through 5, but is shown schematically in FIG. 7 andwill be discussed in detail hereinbelow.

INSTRUMENT CAPSULE 80 Referring specifically to FIG. 6, the instrumentcapsule 80, the various instruments and controls contained therein andthe hookup of the capsule 80 with the separator 12 are illustrateddiagrammatically. A conventional float type pneumatic liquid levelcontroller 160 is disposed within the instrument capsule 80 andconnected to the liquid level controller connections 82 thereof. The oilinlet connection 86 of the capsule 80 is connected internally to the oiloutlet connection 88 thereof by a conduit 162, and a conventionalpneumatic liquid level control valve 164, responsive to the outputcontrol signal generated by the liquid level controller 160 is disposedwithin the conduit 162.

A conduit 166 internally connects the well stream inlet connection 90 ofthe instrument capsule 80 to the well stream outlet connection 92thereof and a conventional normally closed pneumatic safety shut downcontrol valve 168 is disposed in the conduit 166.

A conduit 170 internally connects the gas inlet connection 84 of theinstrument capsule 80 with the gas outlet connection 87 thereof, and aconventional back pressure regulator 172 is disposed in the conduit 170.A conduit 174 is connected to the conduit 170 upstream of the backpressure regulator 172 and a gas dryer 176, preferably a small vesselfilled with a dry desiccant such as activated alumina, is disposed inthe conduit 174. A conventional pressure regulator 178 is disposed inthe conduit 174 downstream of the gas dryer 176, and a conventionalrelief valve 180 is connected to the conduit 174 downstream of theregulator 178. A conduit 182 is connected to the conduit 174 and to theliquid level controller 160 for conducting supply gas to the levelcontroller 160.

A pneumatic control valve 184 for injecting dry gas within the capsule80 is attached to the conduit 174 and a threeway pneumatic control valve186 for operating the well stream safety shut down valve 168 isconnected to the conduit 174. A gas vent connection 188 is provided inthe capsule 80 connected internally to a conduit 190 which includes acheck valve 192 and a downstream pressure regulator 194 disposedtherein.

OPERATION OF THE SEPARATOR 12 AND INSTRUMENT CAPSULE 80 Referring stillto FIG. 6, the well stream from an oil or gas well being produced isflowed by way of the conduit 98, the shutoff valve 102 and the inletconnection 92 of the instrument capsule 80 into the conduit 166contained therein. The well stream passes through the safety shut downvalve 168 disposed in the conduit 166 and then exits the instrumentcapsule 80 by way of the well stream outlet connection 92 thereof. Fromthe capsule 80 the well stream passes by way of the conduit 104 throughthe shutoff valve 112 and into the separator 12 by way of the inletconnection thereof.

The bypass conduit 114 and bypass valve 116 are utilized during initialstart up of the apparatus 10. That is, in order to obtain a supply ofinstrument gas within the capsule and to the three-way control valve 186so that the well stream safety shut down valve 168 can be opened, thesystem is initially pressured up by way of the bypass valve 116 andbypass conduit 114. Once pressure is established within the separator 12and the safety shut down valve 168 opened, the bypass valve 116 isclosed and theother shutoff valves are opened to place the separator 12into operation.

As the well stream flows through the separator 12 it is separated intoits oil and gas components in a conventional manner. The separated oilexits the separator 12 by way of the oil outlet connection 74 thereofand passes by way of the conduit 118 into the instrument capsule 80.That is, the oil flows through the conduit 118, the shutoff valve 120and into the capsule 80 by way of the connection 86 thereof. The oilflows through the conduit 162 and control valve 164 within theinstrument capsule 80 and exits the capsule 80 by way of the oil outletconnection 88 thereof. From the oil outlet connection 88 the oil isflowed by way of the conduit 128 and shutoff valve 129 to storage orfurther processing facilities generally located on an offshore platform.

The level of separated oil existing within the separator 12 isduplicated in the liquid level controller by means of the conduits 146connected to the separator 12, and the controller 160 generates apneumatic control signal which is proportional to variations between theactual level and a preselected desired level. This pneumatic controlsignal is communicated to the control valve 164 by way of the conduit196. As is readily understood by those skilled in the art, the levelcontroller 160 automatically opens and closes the valve 164 so that thedesired oil level is maintained within the separator 12. An adjustinglinkage assembly 202 is connected to the liquid level controller 160from outside the capsule 80 so that the desired liquid level may be setand/or adjusted from outside the capsule 80 during the start up andoperation of the apparatus 10.

The gas separated from the well stream within the separator 12 isremoved therefrom by way of the gas outlet connection 72 thereof. Theseparated gas flows by way of the conduit 132, the shutoff valve 134 andthe connection 84 of the instrument capsule 80 into the conduit 170. Thegas passes by way of the conduit through the back pressure regulator 172and then exits the capsule 80 by way of the gas outlet connection 87thereof. From the gas outlet connection 87 of the capsule 80, the gaspasses through the conduit 142 and shutoff valve 143 to furtherprocessing facilities generally located on an offshore platform. Theback pressure regulator 172 functions to maintain the pressure of theseparator 12 at a desired level in a conventional and well understoodmanner, and an adjusting linkage assembly 173 is connected to theregulator 172 from outside the capsule 80 so that adjustments in backpressure can be made during the start up and operation of the apparatus10.

A portion of the gas passing through the conduit 170 is diverted by wayof the conduit 174 through the gas dryer 176 wherein water contained inthe gas is removed. The dried gas then passes through the pressureregulator 178 wherein the pressure of the gas is preduced to a levelsuch that the gas may be utilized as instrument supply gas. The reliefvalve 180 functions to protect the system downstream of the pressureregulator 178 against over pressure and the conduit 182 leads a portionof the gas passing through the conduit 174 to the level controller 160as supply gas. The remaining gas passes by way of the conduit 174 to thecontrol valves 184 and 186.

The control valve 186 is a conventional pneumatically operated three-wayvalve of the type which may be caused to operate at a selected controlsignal pressure level. The pneumatic control signal generated by theliquid level controller 160 is conducted to the valve 186 by way of aconduit 198 connected to the conduit 196. A conduit 200 connects one ofthe outlet ports of the three-way valve 186 to the pneumatic operator ofthe normally closed well stream safety shut down valve 168. In operationof the control valve 184 it is set so that when the liquid level withinthe separator 12 reaches an abnormally high position and as a result theliquid level controller 160 generates a control signal at a highpressure level, the valve 186 vents the conduit 200 and the operator ofthe valve 168 thereby causing the valve 168 to close and the apparatusto shut down. An adjustment linkage assembly 204 is connected to thecontrol valve 186 from outside the capsule 80 so that the valve 186 maybe reset and adjusted from outside the capsule 80.

In order to insure a water free atmosphere is maintained within theinstrument capsule 80, dehydrated gas is injected into the capsule byway of the control valve 184. The control valve 184 is a conventionalpressure regulator which is responsive to a control signal, andfunctions to maintain the gas pressure level within the instrumentcapsule 80 at a desired increment above the pressure level of the bodyof water outside the instrument capsule 80. The water pressure exertedon the outside of the capsule 80 is communicated by way of the vent 188,the conduit 190 and the conduit 206 to the control valve 184. Thecontrol valve 184 is set to maintain the pressure level within thecapsule 80 at a desired level above the water pressure, i.e., as thewater pressure increases the valve 184 opens to raise the gas pressurelevel within the capsule 80 a corresponding amount and as the waterpressure decreases the control valve 184 closes. The relief valve 194senses the pressure level between it and the check valve 192 andfunctions to relieve pressure from the instrument capsule 80 by way ofthe check valve 192, the conduit 190 and vent 188. Thus, as theapparatus 10 is submerged in a body of water, the control valve 184functions to automatically maintain the gas pressure within the capsule80 at a level above the water pressure outside the capsule. As theapparatus 10 is raised to the surface, the relief valve 194 functions tolower the pressure level back to the original set pressure. That is, asthe water pressure communicated by way of the conduit 190 to the checkvalve 192 decreases, gas pressure between the relief valve 194 and checkvalve 192 decreases causing the pressure regulator 194 to open.

When the instruments within the instrument capsule 80 require servicing,it is unnecessary to raise the entire apparatus 10 to the surface.Instead, the instrument capsule 80 may be removed from the apparatus 10.When removing the instrument capsule 80, the shutoff valves 102, 112,134, 120, 148, 129 and 143 are closed and the bleed valves 110, 138, 152and 124 are opened to insure the relief of pressure contained in thevarious conduits within and connected to the capsule 80. The connectors100, 130, 144, 106, 140, 154 and 126 are next disconnected which allowsthe entire instrument capsule to be removed from the apparatus 10.

As will be understood, in adjusting the instruments contained within theinstrument capsule 80 when starting up and operating the apparatus 10,the observation ports 94 disposed in the instrument capsule are utilizedby a diver to observe the operation of the various instruments, thepressure levels, etc. The instrument adjusting assemblies 173, 202 and204 are utilized by the diver to make appropriate changes in theseparator liquid level, the separator back pressure and the safety shutdown set point.

HYDRAULIC SYSTEM FOR SELECTIVELY MOVING THE BUOYANCY VESSELS 28 AND 30Referring now to FIG. 7, the hydraulic system for moving the buoyancyvessels 28 and 30 is illustrated diagrammatically and is generallydesignated by the numeral 219. The hydraulic jacks 42 and 52 associatedwith the supporting arm assemblies 32 and 34 attached to the buoyancyvessels 28 and 30 are of conventional design. The jack 52 includes acylinder 220 pivotally attached to the supporting arm assembly 34, and apiston assembly 222 is disposed within the cylinder 220 and pivotallyattached to the ballast tank 20. The hydraulic jack 42 is identical tothe jack 52 and includes a cylinder 224 pivotally attached to thesupporting arm assembly 32 and a piston assembly 226 disposed within thecylinder 224 and pivotally attached to the ballast tank 18.

The upper hydraulic ports of the cylinders 220 and 224 are connected byconduits 228 and 230 respectively to a header 232. Shutoff valves 234and 236 are disposed in the conduits 228 and 230 respectively, and theheader 232 is connected by a conduit 238 to the hydraulic fluidaccumulator tank 66. A shutoff valve 240 is disposed in the conduit 238.A body of hydraulic fluid 241 is contained in the tank 66 and theconduit 238 is connected to an internal siphon 67 extending to near thebottom of the tank 66. The lower hydraulic ports of the cylinders 220and 224 are connected by conduits 240 and 242 respectively to a header244. Shutoff valves 246 and 248 are disposed in the conduits 240 and,242respectively, and the header 244 is connected by a conduit 250 having ashutoff valve 252 disposed therein to the hydraulic fluid accumulatortank 64. The tank 64 contains a body of hydraulic fluid 296 and theconduit 250 is connected to an internal siphon 65 which extends to nearthe bottom of the tank 64.

A source of high pressure compressed air, which is preferably comprisedof two or more compressed air bottles 254 removably attached to theapparatus 10, is connected to a conduit 256. A high pressure regulator258 is disposed in the conduit 256, and a conduit 260 is connected tothe conduit 256 downstream of the regulator 258. A shutoff valve 262 isdisposed in the conduit 260 and a hose connection 264 is attached to thevalve 262. A shutoff valve 266 is disposed in the conduit 256 downstreamof the point of connection of the conduit 260, and a low pressureregulator 268 is disposed in the conduit 256 downstream of the shutoffvalve 266. A conduit 270 is connected to the conduit 256 downstream ofthe low pressure regulator 268 for conducting a supply of air to theballast control system to be described in detail below. The end of theconduit 256 is connected to a header 272 which is in turn connected to apair of conduits 274 and 278 having shutoff valves 276 and 280 disposedtherein respectively. The conduit 274 is connected to the tank 66 andthe conduit 278 is connected to the tank 6 4. The accumulator tanks 64and 66 include conduits 222 and 284 respectively attached to the upperportions thereof and shutoff valves 2%6 and 299 are disposed in theconduits 282 and 284 respectively. Hose connections 288 and 292 areattached to the valves 236 and 2% respectively.

OPERATION OF THE HYDRAULIC SYSTEM 219 Referring still to FIG. 7, inoperation of the hydraulic system 219 for moving the buoyancy vessels 28and 30 to alternate desired positions, the high pressure regulator 258is adjusted so that the downstream air pressure is approximately 750psig and the low pressure regulator 268 is adjusted so that the airentering the conduit 270 and the header 272 is at a pressure level ofapproximately 104) psig. A high pressure air hose 294 is connectedbetween the hose connection 264 and one of the hose connections 28% or292 connected to the tanks 64 and 66 respectively, depending upon thedesired direction of movement of the vessels 28 and 30. The use of theflexible hose 294 for providing air to one of the accumulator tanks 64or 66 prevents the application of high pressure air to both tanks 64 and66 simultaneously. Let it be assumed that it is desired to move thebuoyancy vessels 2% and 30 towards the ballast tanks 18 and 20. The hose294 is connected to the hose connector 288 attached to the accumulatortank 64, and the shutoff valve 286 is opened. The shutoff valve 262 isnext opened to apply air pressure from the conduit 256 to the hydraulicfluid accumulator tank 64. As will be understood, when the air pressureis applied to the body of hydraulic fluid 296 contained in the tank 64,the fluid is forced into the conduit 250. The valve 290 attached to thetank 66 is opened to provide an atmospheric vent thereto, and with thevalves 240 and 252 closed, the valves 248, 236, 234 and 246 are opened.The valve 240 disposed in the conduit 238 is next opened, and finallythe valve 252 disposed in the conduit 250 is opened. As the valve 252 isopened, bydraulic fluid is forced through the conduit 250 into theheader 244 through the conduits 24d and 242 and valves 246 and 243 intothe lower portions of the hydraulic cylinders 220 and 224 respectively.The pressure of the hydraulic fluid entering the lower portions of thehydraulic cylinders 226 and 224 forces the hydraulic cylindersdownwardly which in turn moves the supporting arm assemblies 32 34 andbuoyancy vessels 28 and 30 downwardly. As the cylinders 226 and 224 movedownwardly with respect to the pistons 222 and 226, hydraulic fluid isforced out of the upper portions of the cylinders 220 and 224 by way ofthe conduits 228 and 230 respectively. This hydraulic fluid passesthrough the valves 234 and 236 into the header 232 and into theaccumulator tank 66 by way of the conduit 238 and valve 240.

Depending upon whether the apparatus is in or out of water, the forceexerted on the buoyancy vessels 28 and 30 can be upward or downward.That is, when the apparatus 10 is out of the water gravity exerts adownward force on the vessels 28 and 30. When the apparatus 10 is in thewater, the buoyancy of the vessels 28 and 30 exerts an upward forcethereon. This makes a difference only in which of the valves 240 and 252is opened first, i.e., if the apparatus 16 is out of the water the valve240 is opened first and the valve 252 is used to control the movement ofthe vessels 28 and 30. If the apparatus 10 is in the water, the valve252 is opened first and the valve 240 is used to control the movement.

If it is desired to move the buoyancy vessels 28 and 30 in the oppositedirection, i.e., away from the ballast tanks 18 and 20, the valvesmentioned above are closed and the hose 294 is removed from the hoseconnection 288 of the tank 64. The tanks 64 and 66 are vented by openingthe valves 266 and 290, and the hose 294 is connected to the connector292 of the tank 66 and the tank 66 is pressured up by opening the valve262. With the valves 240 and 252 closed, the shutoff valves 248, 236,234 and 246 are opened. The valve 252 is next opened (assuming theapparatus MP is not in the water) and the valve 240 is finally opened toallow hydraulic fluid under pressure to pass by way of the conduit 238,the header 232 and the conduits 228 and 230 into the upper portions ofthe cylinders 226 and 224. The bydraulic fluid entering the upperportions of the cylinders 220 and 224 causes the cylinders, thesupporting arm assemblies 32 and 34 and the buoyancy vessels 28 and 30to move upwardly. The hydraulic fluid forced out of the lower portionsof the cylinders 220 and 224 passes by way of the conduits 246 and 242,the header 244 and the conduit 250 into the accumulator tank 64.

As will be described further herein, when submerging the apparatus 10,the buoyancy vessels 28 and 30 are allowed to move upwardly to theiruppermost position and the hydraulic jacks 42 and 52 function to bufferthe movement, i.e., the jacks act as dash pots. In order to set thehydraulic control system 21% up so that the jacks 42 and 52 act as dashpots, the various hydraulic fluid shutoff valves and vent valvesmentioned above are closed and the hose 294 is removed from the system.The valves 276 and 226 are opened to allow air at a low pressure levelto enter both the tanks 64 and 66 by way of the conduits 274 and 278respectively. The valves 234, 236, 246 and 248 are next opened, and f1nally the valves 252 and 240 are opened. As will be apparent to thoseskilled in the art, the jacks 42 and 52 will now act as dash pots, e.g.,as the vessels 28 and 30 are moved upwardly by the submergence of theapparatus l0, hydraulic fluid is forced by way of the conduits 240 and242, the header 244 and the conduit 250 into the tank 64. Because of thedisplacement of the hydraulic fluid into the tank 64 and thecorresponding movement of fluid out of the tank 66, the upward movementof the vessels 26 and 36 is buffered and the speed at which the vessels2% and 30 move can be controlled by manipulating the valve 252.

BALLAST CONTROL SYSTEM Referring now to FIG. 8, the ballast controlsystem of the apparatus 10 is illustrated diagrammatically and isgenerally designated by the numeral 299. Each of the ballast tanks 18and 20 are divided into a plurality of compartments. Specifically, theballast tank 18 includes a closed compartment 3% at one end, a closedcompartment 362 at the other end, and compartments 304, 306, 30%, 310and 3H2 positioned therebetween. The compartments 394, 306, 308, 316 and312 are closed at the bottom to insure equal distribution of the ballastwater, but are communicated at the top portions thereof. The ballasttank 20 includes a closed compartment 314 at one end, a closedcompartment 316 at the other end and partially closed compartments 318,320, 322, 324 and 326 therebetween. A water intake header 328 isattached to the apparatus which includes a water inlet connectiontherein. Preferably, one of the horizontal support members 26 of theapparatus 10 previously described is used for this purpose. Each of thecompartments of the ballast tanks 18 and 20 are connected to the waterintake header 328 by a separate conduit. That is, the compartments 300,304, 306, 308, 310, 312 and 302 of the ballast tank 18 are connected tothe header 328 by conduits 300, 332, 334, 336, 340 and 342 respectivelyhaving valves 344, 346, 348, 350, 352, 354 and 356 disposed thereinrespectively.

The compartments 314, 318, 320, 322, 324, 326 and 316 of the ballasttank 20 are connectec to the water intake header 328 by conduits 358,360, 362, 364, 366, 368 and 370 respectively having valves 372,. 374,376, 378, 380, 382 and 384 disposed therein respectively.

Each of the closed compartments 300, 302, 314 and 316 of the ballasttanks 18 and 20 are vented to a header 286. That is, the compartment 300is connected to the header 386 by a conduit 388 having a shutoff valve390 disposed therein, the compartment 302 is connected to the header 386by a conduit 392 having a shutoff valve 394 disposed therein, thecompartment 314 of the ballast tank 20 is connected to the header 386 bya conduit 396 having a valve 398 disposed therein and the compartment316 is connected to the header 386 by a conduit 400 having a shutoffvalve 402 disposed therein. The header 386 is connected by a conduit 404to a conduit 406 which is in turn connected to an atmospheric vent 408.A shutoff valve 410 is disposed in the conduit 404.

The central float 160 of the apparatus 10 is connected to the waterintake header 328 by a conduit 412 having a shutoff valve 414 disposedtherein. A vent conduit 416 is connected to the central float 160 and tothe conduit 406. A shutoff valve 418 is disposed in the conduit 416.

The regulator float 162 of the apparatus 10 is connected to the waterintake header 328 by a conduit 420 having a shutoff valve 422 disposedtherein. The regu-. lator float is vented by a conduit 424 which isconnected to the common port of a manually operated three-way valve 426.

The conduit 270, connected to the low pressure air supply describedabove in connection with the hydraulic control system 219, is connectedto a port of the three-way valve 426, and the remaining port isconnected by a conduit 428 having a shutoff valve 429 disposed thereinto the conduit 404. A conduit 430 is connected to the conduit 270 and tothe conduit 404. A shutoff valve 432 is disposed in the conduit 430.

The compartments 304, 306, 308, 310 and 312 of the ballast tank 18 arevented by a conduit 434 and the compartments 318, 320, 322, 324 and 326of the ballast tank 20 are vented by a conduit 438. Both the conduits434 and 438 are connected to a conduit 436 having a shutoff valve 440disposed therein. The conduit 436 is connected to the conduit 406.

OPERATION OF THE BALLAST CONTROL SYSTEM 299 In operation of the ballastcontrol system 299 to bring about the submergence of the apparatus 10,the

central float is flooded by opening the vent valve 418 and the waterintake valve 4l4. When the central float 160 is completely flooded thevalve 414 is closed.

The shutoff valve 440 in the conduit 436 is next opened to vent thecompartments 304, 306, 308, 310 and 312 of the ballast tank 18 and thecompartments 318, 320, 322, 324 and 326 of the ballast tank 20. Thecompartments 304, 306, 308, 310 and 312 of the ballast tank 18 and thecompartments 318, 320, 322, 324 and 326 of the ballast tank 20 aresimultaneously flooded by opening the water intake valves 346, 348, 350,352, 354, 374, 376, 380 and 382. Once the intermediate compartments ofthe ballast tanks 18 and 20 are completely flooded the vent valve 440 isclosed and the various water intake valves corresponding thereto areclosed.

The closed compartments 300, 302, 314 and 316 of the ballast tanks 18and 20 are utilized to trim the apparatus 10 prior to submergence. Thatis, the compartments 300, 302, 314 and 316 are partially filled withwater to bring the apparatus 10 into a horizontal position. Preferably,diagonally opposed compartments 300 and 316 are filled simultaneouslyand then the compartments 302 and 314-are filled. This is accomplishedby opening the valve 410 in the conduit 404 and the valves 390, 394, 398and 402 so that the compartments 300, 302, 314 and 316 are vented. Thewater intake valves 344' and 384 are next opened to allow water to passby way of the conduits 330 and 370 into the compartments 300 and 316.Once the compartments 300 and 316 have been filled to the desired level,the compartments 302 and 314 are filled by opening the water intakevalves 356 and 358, respectively. As will be understood, the particularquantity of water added to each of the compartments 300, 302, 314 and316 is controlled so that the proper amount of water ballast is taken onby the apparatus 10. Further, as mentioned above, the amount of water ineach of the compartments 300, 302, 314 and 316 is adjusted so that theapparatus 10 is trimmed. Once the addition of water ballast to thecompartments 300, 302, 314 and 316 has been completed, the vent valves390, 394, 398 and 402 are closed and the water intake valves 344, 356,372 and 384 are closed.

In the event it is desired to remove some of the water added to any orall of the compartments 300, 302, 314 and 316, this can be accomplishedby opening the valve 432 with the valves 410 and 329 closed so that theair pressure from the conduit 270 is communicated to the header 386 byway of the conduits 404 and 430. One or all of the vent valves 390, 394,398 and 402 are next opened to communicate air pressure to thecompartments 300, 302, 314 and 316 and the appropriate water intakevalves 344, 356, 372 and/or 384 are opened to allow water to flow fromthe compartments into the water intake header 328.

When the addition of water ballast to the ballast tanks 18 and 20 andthe central float 160 has been completed, the three-way valve 426 ispositioned so that the conduit 424 is communicated with the conduit 428and the valves 424 and 410 are opened. The water intake valve 422disposed in the conduit 420 connected to the regulator float 162 is nowopened to cause water ballast to be added to the regulator float 162.Water is added to the regulator float 162 until the apparatus 10 juststarts to sink indicating a negative buoyancy. The water intake valve422 is immediately closed and the three-way valve 426 moved to thealternate position so that air from the conduit 270 is communicated withthe regulator float 162 by way of the conduit 424. The water intakevalve 422 is next opened so that the air pressure within the regulatorfloat 160 forces water therefrominto the water intake header and out ofthe apparatus 10. The valve 422 is allowed to remain open until theapparatus 10 again achieves a positive buoyancy. The apparatus 10 is nowready for submergence and the hydraulic control system 219 should be setup in the manner described above so that the hydraulic jacks 42 and 52act as dash pots and the buoyancy vessels 28 and 30 are free to moveinto their uppermost position as the apparatus 10 submerges.

When all preparations for submergence have been completed, the three-wayvalve 426 is returned to the position whereby the conduit 424 iscommunicated with the conduit 428 and the water intake valve 422 isopened to allow water ballast to enter the regulator float 162 and bringabout the submergence of the apparatus 10. As will be understood, theregulator float 162 is used to control the descent of the apparatus 10in a desired manner by opening and closing the valve 426.

In moving the apparatus 10 to an offshore location, the buoyancy vessels28 and 30 are positioned intermediately as illustrated in FIGS. 1through 4. The removable tie rods 60 are installed between the ends ofthe vessels 28 and 30 and the ballast tanks 1% and 20 to rigidly holdthe vessels 28 and 30 in position while the apparatus 10 is being towed.Towing cables are attached to the lugs 450 attached to the ballast tanks13 and 20 (FIGS. 3 and 4), and the apparatus 10 is towed on the surfaceof the water to the location where it is to be submerged. As will beunderstood, with the buoyancy vessels 28 and 30 at the intermediateposition as shown in FIGS. 1 through 4, the center of buoyancy of theapparatus 10 is above the center of gravity thereof and maximum towingstability is obtained. Once the location where the apparatus is to besubmerged is reached, the tie bars 60 are removed, the ballast tanks areflooded in the manner described above so that the apparatus l submergesand the buoyancy vessels 28 and 30 are moved to their uppermost positionas shown in FIG. 3. When the buoyancy vessels are in the uppermostposition, the center of buoyancy is moved to the greatest possibledistance above the center of gravity of the apparatus thereby impartingmaximum stability to the apparatus while it is submerging. Once theapparatus reaches the bottom of the body of water where it is to beoperated, the vessels 28 and 30 are moved to their lowermost positionadjacent to the ballast tanks 18 and so that they provide support to theapparatus 10. In order to stabilize the apparatus 10 on the bottom, saltwater or other heavier-than-water liquid is pumped into the buoyancyvessels 28 and 30 and ballast tanks 18 and 20.

When it is desired to resurface the apparatus 10 for service orrelocation, the ballast contained in the buoyancy vessels 28 and 30 isdisplaced by compressed air. This can be accomplished by attaching aflexible hose from the hose connector 264 (HO. 7) to connectors on thevessels 28 and 30 (not shown). The buoyancy vessels are allowed to moveto their uppermost position, and the water ballast in the regulatorfloat 162 is displaced with air so that the apparatus 10 again obtains apositive buoyancy and surfaces. Once on the surface, the ballast tanks18 and 20 and the central float 160 are again filled with air to providemaximum buoyancy to the apparatus it).

Thus, the present invention is well adapted to carry out the objects andattain the ends and advantages mentioned as well as those inherenttherein. While presently preferred embodiments of the invention havebeen described for purposes of this disclosure, numerous changes may bemade which will readily suggest themselves to those skilled in the artand which are encompassed within the spirit of the invention as definedby the appended claims.

What is claimed is:

l. A submergible apparatus for producing a well beneath the surface of abody of water which comprises:

an oil and gas separator having a well stream inlet, a gas outlet, anoil outlet and a liquid level controller connection disposed therein;

a pair of elongated horizontal ballast tanks attached to said separator;

means attached to the ballast tanks for selectively filling the tankswith water or air thereby providing ballast or buoyancy to saidapparatus;

a pair of movable buoyancy vessels attached to the separator andpositioned so that the center of buoyancy of said apparatus is above thecenter of gravity thereof;

means attached to the buoyancy vessels for selectively moving thevessels to alternate positions whereby the distance between the'centersof buoyancy and gravity of said apparatus may be changed to providemaximum stability to said apparatus while being towed on the surface ofsaid body of water or submerged therein;

a removable instrument capsule attached to the separator, saidinstrument capsule including a liquid level controller connection andoil inlet and outlet connections;

liquid level control means disposed within the capsule for generating acontrol signal proportional to the variance between the actual liquidlevel within the separator and the desired liquid level, said liquidlevel control means being connected to the liquid level controllerconnection of the capsule;

a conduit removably connecting the liquid level controller connectionsof the separator and the instrument capsule;

a conduit removably connected between the oil outlet oi' the separatorand the oil inlet of the instrument capsule;

valve means responsive to the control signal generated by the liquidlevel control means for controlling the flow rate of oil removed fromthe separator and the liquid level maintained therein, said valve meansbeing disposed within the instrument capsule and connected between theoil inlet and outlet connections thereof; and

means for adjusting the liquid level control means with the respect tothe desired liquid level to be maintained within the separator fromoutside the instrument capsule attached to the liquid level controlmeans and to the instrument capsule.

2. The apparatus of claim E which is further characterized to include:

said instrument capsule including a gas inlet connection and a gasoutlet connection;

terized to include means attached to said instrument capsule forinjecting gas therein and maintaining the pressure thereof at a levelabove the water pressure level exerted on the capsule thereby preventingwater from entering the capsule.

4. The apparatus of claim 3 which is further characterized to includemeans for dehydrating the gas injected into said instrument capsuledisposed within the capsule.

5. The apparatus of claim 4 which is further characterized to include:

said instrument capsule including a well stream inlet connection and awell stream outlet connection; a conduit removably connecting the wellstream outlet connection of the capsule to the well stream inletconnection of the separator;

safety shut down control valve means disposed within the capsule andconnected between the well stream inlet and outlet connections thereof;and

high level control means for operating said safety shut down controlvalve means when the liquid level within the separator reaches apreselected high level, said high level control means being responsiveto the pneumatic signal generated by the liquid level control means andbeing disposed within the instrument capsule and operably connected tothe safety shut down control valve means.

6. The apparatus of claim 5 which is further characterized to includemeans for adjusting the high level control means from outside saidcapsule attached to said capsule and to said high level control means.

7. The apparatus of claim 6 wherein the instrument capsule includes atleast one observation port attached thereto so that the instrumentscontained therein may be observed from outside the' capsule.

8. The apparatus of claim 1 wherein the elongated horizontal ballasttanks are positioned parallel to each other below the oil and gasseparator.

9. The apparatus of claim 8 wherein the movable buoyancy vessels areelongated and are positioned on opposite sides of the separator parallelto the ballast tanks, said buoyancy vessels being movable from positionsadjacent the ballast tanks to positions above the separator.

10. A submergible apparatus for producing an oil well beneath thesurface of a body of water which comprises:

a horizontal oil and gas separator having a well stream inlet, a gasoutlet, an oil outlet and a liquid level controller connection disposedtherein;

a pair of elongated horizontal'ballast tanks attached to the separatorand positioned symmetrically below the separator parallel to the axisthereof;

means attached to the ballast tanks for selectively filling the tankswith water or air thereby providing ballast or buoyancy to saidapparatus;

a pair of elongated movable buoyancy vessels attached to opposite sidesof the separator positioned parallel to the axis of said separator;

means attached to the buoyancy vessels for selectively moving thevessels from positions adjacent the ballast tanks to positions above theseparator so that the distance between the center of buoyancy and thecenter of gravity of the apparatus may be changed to provide maximumstability to the apparatus when being towed on the surface of said bodyof water or submerged therein;

closed instrument capsule attached to the separator, said instrumentcapsule including a liquid level controller connection and oil inlet andoutlet connections;

liquid level control means disposed within the cap- 'sule for generatinga control signal proportional to the variancebetween the actual liquidlevel within the separator and the desired liquid level, said liquidlevel control means being connected to the liquid level controllerconnection of the capsule;

a conduit removably connecting the liquid level controller connectionsof the separator and the instrument capsule;

a conduit removably connected between the oil outlet of the separatorand the oil inlet of the instrument capsule;

valve means responsive to the control signal generated by the liquidlevel control means for controlling the flow rate of oil removed fromthe separator and the liquid level maintained therein, said valve meansbeing disposed within the instrument capsule and connected between theoil inlet and outlet connections thereof; and

means for adjusting the liquid level control means with respect to thedesired liquid level to be maintained within the separator from outsidethe instrument capsule attached to the liquid level control means. andto the instrument capsule.

11. The apparatus of claim 10 which is further characterized to include:

said instrument capsule including a gas inlet connection and a gasoutlet connection;

a conduit removably connected between the gas inlet connection of theinstrument capsule and the gas outlet connection of the separator;

back pressure control means for controlling the gas pressure within theseparator at a desired level disposed within the instrument capsule andconnected between the gas inlet and outlet connections thereof; and

means for adjusting the back pressure control means with respect to thedesired separator pressure level from outside the instrument capsule andto the back pressure control means.

12. The apparatus of claim 11 which is further characterized to includemeans attached to said instrument 5 capsule for injecting gas thereinand maintaining the 13. The apparatus of claim 12 which is furthercharacterized to include means for dehydrating the gas injected intosaid instrument capsule disposed within the level within the separatorreaches a preselected high level, said high level control means beingresponsive to the pneumatic signal generated by the liquid level controlmeans and being disposed within the instrument capsule and operablyconnected to the safety shut down control valve means.

15. The apparatus of claim 14 which is further char acterized to includemeans for adjusting the high level control means from outside saidcapsule attached to said capsule and to said high level control means.

16. The apparatus of claim 15 which is further characterized to includeshutoff valves disposed in the conduits connecting the instrumentcapsule to the separa-

1. A submergible apparatus for producing a well beneath the surface of abody of water which comprises: an oil and gas separator having a wellstream inlet, a gas outlet, an oil outlet and a liquid level controllerconnection disposed therein; a pair of elongated horizontal ballasttanks attached to said separator; means attached to the ballast tanksfor selectively filling the tanks with water or air thereby providingballast or buoyancy to said apparatus; a pair of movable buoyancyvessels attached to the separator and positioned so that the center ofbuoyancy of said apparatus is above the center of gravity thereof; meansattached to the buoyancy vessels for selectively moving the vessels toalternate positions whereby the distance between the centers of buoyancyand gravity of said apparatus may be changed to provide maximumstability to said apparatus while being towed on the surface of saidbody of water or submerged therein; a removable instrument capsuleattached to the separator, said instrument capsule including a liquidlevel controller connection and oil inlet and outlet connections; liquidlevel control means disposed within the capsule for genErating a controlsignal proportional to the variance between the actual liquid levelwithin the separator and the desired liquid level, said liquid levelcontrol means being connected to the liquid level controller connectionof the capsule; a conduit removably connecting the liquid levelcontroller connections of the separator and the instrument capsule; aconduit removably connected between the oil outlet of the separator andthe oil inlet of the instrument capsule; valve means responsive to thecontrol signal generated by the liquid level control means forcontrolling the flow rate of oil removed from the separator and theliquid level maintained therein, said valve means being disposed withinthe instrument capsule and connected between the oil inlet and outletconnections thereof; and means for adjusting the liquid level controlmeans with the respect to the desired liquid level to be maintainedwithin the separator from outside the instrument capsule attached to theliquid level control means and to the instrument capsule.
 2. Theapparatus of claim 1 which is further characterized to include: saidinstrument capsule including a gas inlet connection and a gas outletconnection; a conduit removably connected between the gas inletconnection of the instrument capsule and the gas outlet connection ofthe separator; back pressure control means for controlling the gaspressure within the separator at a desired level disposed within theinstrument capsule and connected between the gas inlet and outletconnections thereof; and means for adjusting the back pressure controlmeans with respect to the desired separator pressure level from outsidethe instrument capsule attached to the instrument capsule and to theback pressure control means.
 3. The apparatus of claim 2 which isfurther characterized to include means attached to said instrumentcapsule for injecting gas therein and maintaining the pressure thereofat a level above the water pressure level exerted on the capsule therebypreventing water from entering the capsule.
 4. The apparatus of claim 3which is further characterized to include means for dehydrating the gasinjected into said instrument capsule disposed within the capsule. 5.The apparatus of claim 4 which is further characterized to include: saidinstrument capsule including a well stream inlet connection and a wellstream outlet connection; a conduit removably connecting the well streamoutlet connection of the capsule to the well stream inlet connection ofthe separator; safety shut down control valve means disposed within thecapsule and connected between the well stream inlet and outletconnections thereof; and high level control means for operating saidsafety shut down control valve means when the liquid level within theseparator reaches a preselected high level, said high level controlmeans being responsive to the pneumatic signal generated by the liquidlevel control means and being disposed within the instrument capsule andoperably connected to the safety shut down control valve means.
 6. Theapparatus of claim 5 which is further characterized to include means foradjusting the high level control means from outside said capsuleattached to said capsule and to said high level control means.
 7. Theapparatus of claim 6 wherein the instrument capsule includes at leastone observation port attached thereto so that the instruments containedtherein may be observed from outside the capsule.
 8. The apparatus ofclaim 1 wherein the elongated horizontal ballast tanks are positionedparallel to each other below the oil and gas separator.
 9. The apparatusof claim 8 wherein the movable buoyancy vessels are elongated and arepositioned on opposite sides of the separator parallel to the ballasttanks, said buoyancy vessels being movable from positions adjacent theballast tanks to positions above the separator.
 10. A submergibleapparatus for producing aN oil well beneath the surface of a body ofwater which comprises: a horizontal oil and gas separator having a wellstream inlet, a gas outlet, an oil outlet and a liquid level controllerconnection disposed therein; a pair of elongated horizontal ballasttanks attached to the separator and positioned symmetrically below theseparator parallel to the axis thereof; means attached to the ballasttanks for selectively filling the tanks with water or air therebyproviding ballast or buoyancy to said apparatus; a pair of elongatedmovable buoyancy vessels attached to opposite sides of the separatorpositioned parallel to the axis of said separator; means attached to thebuoyancy vessels for selectively moving the vessels from positionsadjacent the ballast tanks to positions above the separator so that thedistance between the center of buoyancy and the center of gravity of theapparatus may be changed to provide maximum stability to the apparatuswhen being towed on the surface of said body of water or submergedtherein; a closed instrument capsule attached to the separator, saidinstrument capsule including a liquid level controller connection andoil inlet and outlet connections; liquid level control means disposedwithin the capsule for generating a control signal proportional to thevariance between the actual liquid level within the separator and thedesired liquid level, said liquid level control means being connected tothe liquid level controller connection of the capsule; a conduitremovably connecting the liquid level controller connections of theseparator and the instrument capsule; a conduit removably connectedbetween the oil outlet of the separator and the oil inlet of theinstrument capsule; valve means responsive to the control signalgenerated by the liquid level control means for controlling the flowrate of oil removed from the separator and the liquid level maintainedtherein, said valve means being disposed within the instrument capsuleand connected between the oil inlet and outlet connections thereof; andmeans for adjusting the liquid level control means with respect to thedesired liquid level to be maintained within the separator from outsidethe instrument capsule attached to the liquid level control means and tothe instrument capsule.
 11. The apparatus of claim 10 which is furthercharacterized to include: said instrument capsule including a gas inletconnection and a gas outlet connection; a conduit removably connectedbetween the gas inlet connection of the instrument capsule and the gasoutlet connection of the separator; back pressure control means forcontrolling the gas pressure within the separator at a desired leveldisposed within the instrument capsule and connected between the gasinlet and outlet connections thereof; and means for adjusting the backpressure control means with respect to the desired separator pressurelevel from outside the instrument capsule and to the back pressurecontrol means.
 12. The apparatus of claim 11 which is furthercharacterized to include means attached to said instrument capsule forinjecting gas therein and maintaining the pressure thereof at a levelabove the water pressure level exerted on the capsule thereby preventingwater from entering the capsule.
 13. The apparatus of claim 12 which isfurther characterized to include means for dehydrating the gas injectedinto said instrument capsule disposed within the capsule.
 14. Theapparatus of claim 13 which is further characterized to include: saidinstrument capsule including a well stream inlet connection and a wellstream outlet connection; a conduit removably connecting the well streamoutlet connection of the capsule to the well stream inlet connection ofthe separator; safety shut down control valve means disposed within thecapsule and connected between the well stream inlet and outletconnections thereof; and high level control meAns for operating saidsafety shut down control valve means when the liquid level within theseparator reaches a preselected high level, said high level controlmeans being responsive to the pneumatic signal generated by the liquidlevel control means and being disposed within the instrument capsule andoperably connected to the safety shut down control valve means.
 15. Theapparatus of claim 14 which is further characterized to include meansfor adjusting the high level control means from outside said capsuleattached to said capsule and to said high level control means.
 16. Theapparatus of claim 15 which is further characterized to include shutoffvalves disposed in the conduits connecting the instrument capsule to theseparator.